CN103227420A - Spark plug for internal combustion engine - Google Patents
Spark plug for internal combustion engine Download PDFInfo
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- CN103227420A CN103227420A CN2013100491225A CN201310049122A CN103227420A CN 103227420 A CN103227420 A CN 103227420A CN 2013100491225 A CN2013100491225 A CN 2013100491225A CN 201310049122 A CN201310049122 A CN 201310049122A CN 103227420 A CN103227420 A CN 103227420A
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
- H01T13/00—Sparking plugs
- H01T13/02—Details
- H01T13/08—Mounting, fixing or sealing of sparking plugs, e.g. in combustion chamber
Abstract
Provided is a spark plug for an internal combustion engine capable of ensuring sufficient gastightness of a combustion chamber and meeting demand for a reduction in diameter. A spark plug (1) includes a center electrode (5), an insulator (2) provided externally of the outer circumference of the center electrode (5), a metallic shell (3) provided externally of the outer circumference of the insulator (2), and a ground electrode (27) extending from a front end portion of the metallic shell (3). The metallic shell (3) has, on an outer circumferential surface thereof, a threaded portion (15) to be threadingly engaged with a mounting hole (43) of a head (42) of an internal combustion engine (41), a screw neck 16 located rearward of the threaded portion 15, a diameter-expanded portion (18) greater in diameter than the screw neck 16, and a seat portion (17) connectingly extending between the screw neck (16) and the diameter-expanded portion (18). When the threaded portion (15) is threadingly engaged with the mounting hole (43), the seat portion (17) comes in close contact with the head (42). The threaded portion 15 has a thread diameter of M14 or less. The seat portion 17 has a predetermined value or less of Vickers hardness and is higher in hardness than a portion of the head (42) which comes into contact with the seat portion (17).
Description
The application be priority date be January 23, the applying date in 2009 be on January 21st, 2010, on June 17th, 2011 enter the China national stage, the PCT application number is PCT/JP2010/050683, Chinese application number is 201080003648.4, denomination of invention is divided an application for the application of " ignition plug for I. C. engine ".
Technical field
The present invention relates to the spark plug that uses in a kind of internal combustion engine.
Background technology
Spark plug is installed on the internal combustion engine (engine), is used for the sparking of the mist in the combustion chamber.Generally speaking, spark plug has: insulator, and it has the axis hole that extends along axis direction; Central electrode is inserted and is led in this axis hole; The main body accessory is arranged on the periphery of insulator.And be formed with on the outer peripheral face of main body accessory: the threaded portion is used for screwing togather with the installing hole of the head of internal combustion engine; Screw neck is from the distolateral backward extension in the rear end of above-mentioned threaded portion; Wide diameter portion is formed on the rear end side of screw neck, and diameter is bigger than above-mentioned screw neck; And seat portion, connect above-mentioned screw neck and wide diameter portion.And, on the periphery of above-mentioned screw neck, with above-mentioned seat portion butt the packing ring of annular is set.And when spark plug was installed to internal combustion engine, by the axle power of screw thread couple, above-mentioned packing ring closely was contacted with the head of above-mentioned internal combustion engine, thereby kept the air-tightness (for example with reference to patent documentation 1 etc.) in the combustion chamber.
And from realizing better bubble-tight angle, can be liner is not set, makes above-mentioned seat portion and the directly tight formation that contacts of head (for example with reference to patent documentation 2 etc.).
Patent documentation 1: the spy opens the 2008-108478 communique
Patent documentation 2: the spy opens the 2001-118659 communique
Summary of the invention
But in such spark plug, can destroy air-tightness because of the tiny damage of seat portion, head, strain etc.
And in the last few years,, required the miniaturization (pathization) of spark plug, can make wide diameter portion, the threaded portion pathization of aforementioned body accessory from improving the layout degree of freedom equal angles of engine head.At this, be accompanied by the pathization of wide diameter portion, the area of seat portion must reduce, and along with the pathization of threaded portion, the axle power that screw thread couple produces can reduce.That is, in the spark plug of pathization, be difficult to fully to guarantee the sealing between a portion and the head, and then cause the air-tightness in the combustion chamber to descend easily.
The present invention occurs in view of above situation, and its purpose is to provide a kind of guarantees the sufficient air-tightness in the combustion chamber, and can satisfy the ignition plug for I. C. engine of path demand.
Below each that is suitable for realizing above-mentioned purpose constituted subitem describe.And, as required the formation of correspondence is recorded and narrated its distinctive action effect.
The ignition plug for I. C. engine that constitutes 1. formations has:
The bar-shaped central electrode that on axis direction, extends;
Be arranged on the insulator roughly cylindraceous of the periphery of above-mentioned central electrode;
Be arranged on the roughly cylindrical main body accessory of above-mentioned insulator periphery; And
Grounding electrode extends from the leading section of aforementioned body accessory, and self leading section and the leading section of above-mentioned central electrode between form the gap,
Outer peripheral face at the aforementioned body accessory is formed with:
The threaded portion that screws togather with the installing hole of the head of internal combustion engine;
Be formed on the screw neck of the rear end side of above-mentioned threaded portion;
Be formed on the rear end side of above-mentioned screw neck, the wide diameter portion that diameter is bigger than above-mentioned screw neck; And
Seat portion between above-mentioned screw neck and above-mentioned wide diameter portion,
And when the installing hole of the head of above-mentioned threaded portion and above-mentioned internal combustion engine screwed togather, above-mentioned seat portion closely contacted with above-mentioned head,
It is characterized in that,
The threading path of above-mentioned threaded portion is M14,
The Vickers hardness of the hardness of above-mentioned seat portion is below the 250Hv, and greater than the hardness of the part that contacts with above-mentioned seat portion in the above-mentioned head.
According to above-mentioned formation 1, the hardness of seat portion is greater than the hardness of the part that contacts with seat portion in the head.Therefore, when head is carried out repeatedly installation of spark plug/take off etc., can effectively suppress to be accompanied by plastic deformation with the seat portion that contacts of head.Therefore and the Vickers hardness of the hardness at the position that contacts with head in the seat portion is below the 250Hv, even carry out repeatedly the installation of spark plug/take off when waiting, head also is difficult for producing being out of shape.
Therefore constitute 1 according to this, can prevent conscientiously from the damage of guaranteeing bubble-tight angle very important seat portion and head, strain etc.The result is conscientiously between seal receptacle portion and the head, and then realizes good air-tightness in the combustion chamber.
In addition, in the installation constitution of the ignition plug for I. C. engine that forms in that ignition plug for I. C. engine is installed to the head of internal combustion engine, above-mentioned technological thought can be specialized.
The ignition plug for I. C. engine that constitutes 2. formations is characterised in that, in above-mentioned formation 1,
The threading path of above-mentioned threaded portion is below the M12,
The Vickers hardness of the hardness of above-mentioned seat portion is below the 200Hv.
During the threading path path of threaded portion, in view of the intensity of threaded portion, must make when spark plug is assembled into internal combustion engine to conclude torque less.If but it is less to conclude torque, then axle power reduces.Therefore, the tight contact of the relative head of seat portion becomes insufficient, and the air-tightness in the combustion chamber may reduce.And, when the threading path path of threaded portion, leading edge deformation easily takes place when repeatedly carrying out the installation of spark plug/take off etc.
Therefore, shown in above-mentioned formation 2, the threading path of threaded portion be the following pathization of M12 spark plug as mentioned above, though air-tightness more may descend, according to this formation 2, the Vickers hardness of the hardness of the part that contacts with head in the seat portion is below the 200Hv.Therefore, can make a portion closely be contacted with head more effectively, conscientiously between seal receptacle portion and the head.And, when installation of repeatedly carrying out spark plug/take off etc., can prevent leading edge deformation conscientiously.The result can guarantee good air-tightness in the combustion chamber.
The ignition plug for I. C. engine that constitutes 3. formations is characterised in that, in above-mentioned formation 1 or 2, in the above-mentioned seat portion, 10 mean roughness on the surface, position that contacts with above-mentioned head are below the 12.5 μ m.
According to above-mentioned formation 3,10 mean roughness on the surface, position that contacts with head in the seat portion are below the 12.5 μ m.Therefore, can make a portion closely be contacted with head more effectively, further improve the air-tightness in the combustion chamber.
The ignition plug for I. C. engine that constitutes 4. formations is characterised in that, in any of above-mentioned formation 1 to 3, form connecting portion on the outer peripheral face of aforementioned body accessory, the front end of the above-mentioned seat of this connecting portion connection portion and the rear end of above-mentioned screw neck, and in comprising the cross section of above-mentioned axis, this connecting portion and above-mentioned axis angulation are greater than above-mentioned axis and above-mentioned seat portion angulation
If the external diameter of the part that the external diameter of above-mentioned wide diameter portion is the external diameter of A, above-mentioned screw neck to become minimum is the external diameter of the boundary member of B, above-mentioned seat portion and above-mentioned connecting portion when being C, satisfy following formula (1) and formula (2):
（C－B）/2≥0.3mm……（1）
（A－C）/2≥0.7mm……（2）。
When the area of above-mentioned seat portion is big, closely be contacted with head in order to make a portion, need further to increase the power of concluding when spark plug is installed.But in the spark plug of pathization etc., need reduce and conclude power, increase and conclude power and not necessarily be easy to.
In view of this point,, make that connecting portion does not contact head, only seat portion constitutes in intimate contact by above-mentioned formation 4.So, compare when whole of the position that is equivalent to a portion and connecting portion closely is contacted with head, can reduce the area at the position that closely contacts with head.The result is, need not increase the power of concluding when spark plug is installed, and can make spark plug (seat portion) closely be contacted with head more effectively, more easily realizes good air-tightness in the combustion chamber.
In addition, (C-B)/during 2＜0.3mm, even when the area of connecting portion reduces relatively, the area of seat portion must increase, and above-mentioned action effect possibly can't be given full play to.And when working as (A-C)/2＜0.7mm, that is, when seat portion area was too small, even seat portion closely is contacted with head securely, it is insufficient that the sealing between seat portion and head also becomes, and the air-tightness in the combustion chamber may reduce.
In addition, above-mentioned formation 4 is especially effective in the spark plug that the threading path path turns to below the M12 and the area at seat portion and the pairing position of connecting portion is bigger.Promptly there is following situation: even under situation, because of the instrument buckling parts being diminished, so that can't make wide diameter portion and threaded portion pathization in the lump with the relation of the instrument that uses etc. with the threaded portion pathization.In this case, the area at the position corresponding with seat portion and connecting portion increases, and on the other hand, along with the pathization of screw thread, need make and conclude power and further reduce.That is, the threaded portion is in the spark plug that increases of the area at following pathization of M12 and the position corresponding with seat portion and connecting portion, guarantees that the air-tightness the combustion chamber in is very difficult.And, as mentioned above, can reduce the area at the position that closely contacts with head by above-mentioned formation 4.Therefore, even the less power of concluding the when spark plug of pathization is installed also can fully be guaranteed the sealing between a portion and head.
The ignition plug for I. C. engine that constitutes 5. formations is characterised in that, in above-mentioned formation 4, make axis in the cross section that comprises above-mentioned axis, above-mentioned and above-mentioned seat portion angulation be 60 degree above, 70 spend below.
According to above-mentioned formation 5, axis and seat portion angulation (seat portion angle) be 60 spend more than, so can prevent that the portion from biting into head, even in the installation of repeatedly carrying out spark plug/when taking off, also can guarantee good air-tightness.On the other hand, because of seat portion angle is below 70 degree,, can realize good air-tightness so can fully improve the tight contact of a portion to head.
The ignition plug for I. C. engine that constitutes 6. formations has:
The bar-shaped central electrode that on axis direction, extends;
Be arranged on the insulator roughly cylindraceous of the periphery of above-mentioned central electrode;
Be arranged on the roughly cylindrical main body accessory of above-mentioned insulator periphery; And
Grounding electrode from the leading section extension of aforementioned body accessory, and forms the gap between the leading section of leading section of self and above-mentioned central electrode,
On the outer peripheral face of aforementioned body accessory, be formed with:
The threaded portion that screws togather with the installing hole of the head of internal combustion engine;
Be formed on the screw neck of the rear end side of above-mentioned threaded portion;
Be formed on the rear end side of above-mentioned screw neck, the wide diameter portion that diameter is bigger than above-mentioned screw neck; And
Seat portion between above-mentioned screw neck and above-mentioned wide diameter portion,
It is characterized in that,
The surface of above-mentioned seat portion is provided with coating, and this coating covers this surface, and when the installing hole of the head of above-mentioned threaded portion and above-mentioned internal combustion engine screws togather, closely contacts with above-mentioned head,
Above-mentioned coating forms by following material: its softening point is more than 200 ℃, and the hardness of the part that contacts with above-mentioned coating in the above-mentioned head of hardness ratio is little.
According to above-mentioned formation 6, therefore the hardness of coating can make coating more closely be contacted with head, and can suppress the damage of head conscientiously less than the hardness of the part that contacts with above-mentioned coating in the head.And the softening point that forms the material of coating is more than 200 ℃, therefore under the hot environment when spark plug uses, can suppress the thermal deformation of coating.That is,, can fully guarantee air-tightness in the combustion chamber by these action effects according to this formation 6.
In addition, material as forming coating for example comprises: metal materials such as thermal endurance rubber (for example fluorubber etc.), heat-resistant resin (for example polyamide-based resin, polyimides are resin, fluororesin or PETG (PET) for the mylar of representative etc.) or zinc etc.And in these materials, because of the material of elastically deformable the relative head of spark plug is repeatedly being installed/when taking off, also can prevent the distortion of coating, therefore preferred the use.
And shown in above-mentioned formation 4 grades, in having the spark plug of connecting portion, also applicable constitutes 6 technological thought, covers the portion of the seat at least surface of seat portion and connecting portion with coating.
The ignition plug for I. C. engine that constitutes 7. formations is characterised in that in above-mentioned formation 6, the Vickers hardness of the hardness of above-mentioned coating is below the 100Hv,
And 10 mean roughness on the surface, position that contacts with above-mentioned head in the above-mentioned coating are below the 12.5 μ m.
According to above-mentioned formation 7, the Vickers hardness of the hardness at the position that contacts with head in the coating is below the 100Hv, and 10 mean roughness on the surface, position that contacts with head in the above-mentioned coating are below the 12.5 μ m.Therefore, can make spark plug (coating) closely be contacted with head more effectively, further improve the air-tightness in the combustion chamber.
The ignition plug for I. C. engine that constitutes 8. formations is characterised in that in above-mentioned formation 6 or 7, above-mentioned coating has the thickness that 5 μ m are above, 300 μ m are following.
According to above-mentioned formation 8, cover seat portion surface, be provided with coating with the above thickness of 5 μ m, therefore can make a portion (coating) closely be contacted with head more effectively.The result can further improve air-tightness.
In addition, when the thickness of coating surpassed 300 μ m, the tight contact of seat portion and coating was destroyed, descended because of these reasons can cause air-tightness.Therefore, the thickness of preferred coating is below the 300 μ m.
Description of drawings
Fig. 1 is that the part of the formation of the spark plug in expression the 1st execution mode is blocked front view.
Fig. 2 is that the expression spark plug blocks front view to the part of the installment state of internal combustion engine.
Fig. 3 is that the expression threading path is the result's of the air-tightness evaluation test in the sample of M14 a chart.
Fig. 4 is that the expression threading path is the result's of the air-tightness evaluation test in the sample of M12 a chart.
Fig. 5 is that the expression threading path is the result's of the air-tightness evaluation test in the sample of M10 a chart.
Fig. 6 is expression seat portion's surface roughness and the minimum chart of the relation of torque of concluding.
Fig. 7 is that the part of the formation of the spark plug in expression the 2nd execution mode is blocked front view.
Fig. 8 is the part amplification sectional view of the formation of the coating in expression the 2nd execution mode.
Fig. 9 is expression coating (seat portion) surface roughness and the minimum chart of the relation of torque of concluding.
Figure 10 is expression coating thickness and the minimum relation of torque, the material that reaches the formation coating and the minimum chart of the relation of torque of concluding concluded.
Figure 11 is that the part of the formation of the spark plug in expression the 3rd execution mode is blocked front view.
Figure 12 is the part amplification sectional view of the formation of explanation seat portion and connecting portion etc.
Figure 13 is that the part that the expression spark plug is installed to the installment state of internal combustion engine is blocked enlarged front view.
Figure 14 is that the part of the formation of the spark plug in expression the 4th execution mode is blocked front view.
Figure 15 is the part amplification sectional view of the formation of the coating of explanation in the 4th execution mode etc.
The explanation of mark
1,1A, 1B, 1C: spark plug (ignition plug for I. C. engine)
2: insulating part (insulator)
3: the main body accessory
4: axis hole
5: central electrode
15: the threaded portion
16: screw neck
17,17A, 47,47A: seat portion
17B: connecting portion
18: wide diameter portion
26: the leading section of main body accessory
27: grounding electrode
41: internal combustion engine
42: head
43: installing hole
51A, 51B: coating
CL1: axis
Embodiment
(the 1st execution mode)
Following with reference to the description of drawings execution mode.Fig. 1 is that the part of expression ignition plug for I. C. engine (hereinafter referred to as " spark plug ") 1 is blocked front view.Among this external Fig. 1, be that the above-below direction in the accompanying drawing, front, the upside that downside is spark plug 1 are that rear end side describes with the axis CL1 direction of spark plug 1.
Spark plug 1 is made of tubular insulating part 1 as insulator, the cylindrical main body accessory 3 etc. that keeps it.
As everyone knows, insulating part 2 forms by firing aluminium oxide etc., has in its profile portion: the rear end side main part 10 that is formed on rear end side; Compare with this rear end side main part 10 and to be positioned at front, the large-diameter portion 11 that goes out to form to the external diameter evagination; Compare with this large-diameter portion 11 and to be positioned at front, the mid-section body portion 12 that forms than its ground, thin footpath; Compare with this mid-section body portion 12 and to be positioned at front, form than its ground, thin footpath considerable 13.And, in the insulating part 2, large-diameter portion 11, mid-section body portion 12 and most of considerable 13 inside that is housed in main body accessory 3.And, be formed with the stage portion 14 of taper at the connecting portion of considerable 13 and mid-section body portion 12, by this stage portion 14, insulating part 2 engages to main body accessory 3.
Further, in the insulating part 2, connect formation axis hole 4 along axis CL1, central electrode 5 inserts, is fixed to the front of this axis hole 4.This central electrode 5 is made of following: the internal layer 5A that is made of copper or copper alloy; And by the outer 5B that with nickel (Ni) is the Ni alloy formation of main component.And central electrode 5 integral body are bar-shaped (cylindric), and its front end face is formed flatly, and outstanding from the front end of insulating part 2.
And terminal electrode 6 inserts, is fixed to the rear end side of axis hole 4 under the state outstanding from the rear end of insulating part 2.
Further, between the central electrode 5 and terminal electrode 6 of axis hole 4, be provided with columned resistive element 7.The both ends of this resistive element 7 are electrically connected to central electrode 5 and terminal electrode 6 respectively by the glass seal layer 8,9 of conductivity.
And aforementioned body accessory 3 forms tubular by metals such as mild steel.On the outer peripheral face of main body accessory 3,, from the front to the rear end side, be provided with successively: threaded portion 15, screw neck 16, seat portion 17 and wide diameter portion 18 along axis CL1.
Above-mentioned threaded portion 15 is used to be screwed to the installing hole 43 of the head 42 of following internal combustion engine 41, and in the present embodiment, the threading path of above-mentioned threaded portion 15 is M14.And above-mentioned screw neck 16 begins continuous formation from the rear end of above-mentioned threaded portion 15, is cylindric than the threading path path of threaded portion 15.Further, above-mentioned seat portion 17 forms the front end of the rear end of connecting thread neck 16 and wide diameter portion 18 to the direction rear end side hole enlargement of axis CL1.In addition, in the cross section that comprises above-mentioned axis CL1, make the big portion 17 that forms of the object line of above-mentioned seat portion 17 and above-mentioned axis CL1 angulation (for example above 90 degree of 60 degree are following).Further, wide diameter portion 18 is cylindric from the distolateral backward extension in rear end of above-mentioned seat portion 17.And, in the rear end side of above-mentioned wide diameter portion 18 the instrument buckling parts 19 of cross section hexagonal configuration being set, it is used for when spark plug 1 is installed to engine head, fastens instruments such as spanner.And the rearward end of main body accessory 3 is provided with the caulking part 20 that is used to keep insulating part 2.
Further, the inner peripheral surface of main body accessory 3 is provided with the stage portion 21 of taper, is used for insulating part 2 cards are ended.And, insulating part 2 is from the distolateral forward insertion of the rear end side of main body accessory 3, engage in self stage portion 14 under the state of stage portion 21 of main body accessory 3, the peristome of the rear end side by making main body accessory 3 is to the radially inner side riveted joint, promptly fix by forming above-mentioned caulking part 20.In addition, between insulating part 2 and main body accessory 3 both sides' stage portion 14,21, getting involved has circular plate liner 22.So, can keep the air-tightness in the combustion chamber, make the combustion air in gap of the inner peripheral surface of considerable 13 of entering into the insulating part 2 that is exposed in the combustion chamber and main body accessory 3 not leak into the outside.
Further, airtight more complete for what riveted joint was formed, in the rear end side of main body accessory 3, between main body accessory 3 and insulating part 2, get involved the annular element 23,24 that ring-type is arranged, between annular element 23,24, fill the powder of talcum (タ Le Network) 25.That is, main body accessory 3 keeps insulating part 2 by plate liner 22, annular element 23,24 and talcum 25.
And, be combined with grounding electrode 27 on the leading section 26 of main body accessory 3, the roughly bent intermediate of this grounding electrode self, the front side of self is relative with the leading section of central electrode 5.Grounding electrode 27 is following double-layer structurals: by Ni alloy (for example inconel 600, inconel 601(イ Application コ ネ Le 600, イ Application コ ネ Le 601 are registered trade mark)) the outer 27A that constitutes; And by the copper alloy of the conduct metal electrically stronger or the internal layer 27B that fine copper constitutes than the heat conduction of above-mentioned Ni alloy.And, between the leading section and grounding electrode 27 of above-mentioned central electrode 5, form spark-discharge gap 33, in this spark-discharge gap 33, roughly along carrying out sparkover on the direction of above-mentioned axis CL1 as the gap.
Further, in the present embodiment, as shown in Figure 2, when the installing hole 43 of the head 42 that above-mentioned threaded portion 15 is installed to internal combustion engine 41, closely be contacted with above-mentioned head 42, keep the air-tightness in the combustion chamber by above-mentioned seat portion 17.And the hardness of above-mentioned seat portion 17 is expressed as (for example 180Hv) below the 250Hv by adopting following manufacture method with Vickers hardness.On the other hand, above-mentioned head 42 is by with aluminium being the alloy formation of the softer (for example 100Hv) of main component.Therefore, the hardness of seat portion 17 is greater than the hardness of head 42.
And 10 mean roughness on above-mentioned seat portion 17 surfaces are 12.5 μ m following (for example 10 μ m), and are more level and smooth.In addition, 10 mean roughness are specification with JIS B0601.
And, also can make the threading path pathization of threaded portion 15.But the threading path of threaded portion 15 is when to be M12 following, and the Vickers hardness of the hardness of seat portion 17 is below the 200Hv.
The manufacture method of the spark plug 1 that as above constitutes then is described.Process main body accessory 3 at first in advance.That is,, form through hole by columned metal material (for example such ferrous material, the stainless steel material of S17C, S25C) is implemented cut, and finishing appearance, main body accessory intermediate obtained.Therefore, the main body accessory intermediate in the present embodiment only forms by implementing cut, and the result can suppress to be equivalent to the hardness rising at the position of above-mentioned seat portion 17.
Then, the straight bar-shaped grounding electrode 27 that resistance welded is made of the Ni alloy on the front end face of main body accessory intermediate.When carrying out this welding, produce so-called " drip ", therefore after " drip " is somebody's turn to do in removal, on the regulation position of main body accessory intermediate, form threaded portion 15 by rolling.Further, by attrition process etc. is implemented at the position that is equivalent to above-mentioned seat portion 17,10 mean roughness that obtain above-mentioned seat portion 17 surfaces are below the 12.5 μ m, welded the main body accessory 3 of grounding electrode 27.In addition, also can implement zinc-plated or nickel plating to the main body accessory 3 that has welded grounding electrode 27.And,, also can further implement chromate and handle its surface in order to improve corrosion resistance.
On the other hand, different with aforementioned body accessory 3, insulating part 2 is carried out processing and forming.For example, use with aluminium oxide as main body, contain the material powder of adhesive etc., the modulation moulding uses it to carry out the rubber punch forming with former granulation thing, thus the formed body of acquisition tubular.And, the formed body that obtains is being implemented on the basis of attrition process and shaping, by implementing to fire processing, obtain insulating part 2.
And, be independent of aforementioned body accessory 3, insulating part 2, produce central electrode 5.That is, the Ni alloy that central portion has been disposed the copper alloy that is used to improve heat dispersion forges processing, produces central electrode 5.
And as above insulating part 2 of Huo Deing and central electrode 5, resistive element 7, terminal electrode 6 are by glass seal layer 8,9 sealed fixing.As glass seal layer 8,9, general mix pyrex and metal dust and modulation, the material clamping resistive element 7 that this modulate, be injected into the axis hole 4 of insulating part 2 interior after, from the rear time, in baking furnace, fire and solidify by heating by 6 extruding of above-mentioned terminal electrode.And this moment, can fire glaze layer simultaneously to the surface of the rear end side main part 10 of insulating part 2, also can form glaze layer in advance.
Afterwards, have respectively the central electrode 5 as above made and terminal electrode 6 insulating part 2, have a grounding electrode 27 main body accessory 3 assembled.Particularly, the peristome of the rear end side by the main body accessory 3 that will form than thin-walled ground is riveted to radially inner side, promptly fixes by forming above-mentioned caulking part 20.
And the fore-end by making grounding electrode 27 is to central electrode 5 one lateral bending songs at last, implements to adjust central electrode 5, and the processing of the above-mentioned spark-discharge gap 33 of 27 of grounding electrodes, obtains above-mentioned spark plug 1.
As explained in detail above, according to present embodiment, the hardness of seat portion 17 is greater than the hardness of head 42.Therefore, even when repeatedly carrying out the installation of spark plug 1, taking off etc., also can effectively suppress to be accompanied by plastic deformation with the seat portion 17 that contacts of head to head 42.And the Vickers hardness of the hardness of seat portion 17 is 250Hv following (threading path of threaded portion 15 is that M12 is when following, below 200Hv), so when the installation of repeatedly carrying out spark plug/take off etc., head 42 also is difficult to deform.
Therefore according to present embodiment, can prevent conscientiously from the damage of guaranteeing the very important seat of bubble-tight angle portion 17 in the combustion chamber and head 42, strain etc.The result is conscientiously between seal receptacle portion 17 and the head 42, and realizes good air-tightness in the combustion chamber.
And the Vickers hardness of the hardness of seat portion 17 is 200Hv when following, can further prevent damage, strain of a portion 17 and head 42 etc. conscientiously, and can make a portion 17 closely be contacted with head 42 more effectively.Thus, can further improve air-tightness in the combustion chamber.
Further, 10 mean roughness on seat portion 17 surfaces are below the 12.5 μ m, therefore can make a portion 17 closely be contacted with head 42 more effectively, further improve the air-tightness in the combustion chamber.
And for seat portion 17, its object line and above-mentioned axis CL1 form the angle that is bigger.So, when spark plug 1 is installed to internal combustion engine 41, can prevent more effectively that the portion 17 from biting into head 42, realize bubble-tight further raising.
Then the action effect in order to confirm that above-mentioned execution mode plays has carried out the air-tightness evaluation test.The summary of air-tightness evaluation test is as follows.That is, the hardness that produces the threading path of double thread portion and seat portion is carried out the sample of the spark plug of various changes, and makes the testing stand simulated engine head, that the hardness (hardness of head) at the position that contacts with seat portion carried out the aluminum of various changes.And, the conclude torque of sample with 15Nm is installed on the testing stand, and when each sample is heated to 150 ℃, passing through under the pressure status of air persistent pressure 1.5MPa, mensuration is from the per 1 minute leakage of air amount (ml/ branch) between sample and testing stand, at last sample is taken off from testing stand, to each sample carry out 5 times (that is, to same testing stand respectively carry out 5 same samples installation, take off).Wherein, whole 5 times the test in, when air leakage rate less than the 2ml/ timesharing, think and can realize good air-tightness, make the evaluation of " zero ", and when the leakage of air amount be that number of times more than 2ml/ divides is more than 1 time the time, think that air-tightness is insufficient, make the evaluation of " * ".And, when test back validation test platform has distortion, think the possibility that has the air-tightness deficiency in the combustion chamber, make the evaluation of " ■ ".Fig. 3 ~ Fig. 5 represents the result of air-tightness evaluation test.In addition, the result of the test when Fig. 3 represents that the threading path of sample is M14, the result of the test when Fig. 4 represents that threading path is M12.And, the result of the test when Fig. 5 represents that threading path is M10.
As Fig. 3 ~ shown in Figure 5, the hardness of seat portion is during less than the hardness of head, and the air-tightness in the combustion chamber is insufficient as can be known.Can think this be because, the hardness by making a portion is less than the hardness of head, the easy plastic deformation of seat portion is installed/distortion of seat portion when taking off spark plug becomes obvious repeatedly.
Relative with it, be sample more than the head hardness for seat portion hardness, it has realized good air-tightness as can be known.This be because, be more than the head hardness by making portion's hardness, can suppress the plastic deformation of a portion as far as possible.But the threading path of threaded portion be in the sample of M14 seat portion hardness surpass 250Hv, and the threading path of threaded portion be the hardness of seat portion in the following sample of M12 above 200Hv, confirmed distortion in the testing stand after the test.Therefore, we can say, in order in the combustion chamber, to guarantee good air-tightness, the hardness that makes a portion is greater than the hardness of head and when making the threading path of threaded portion be M14, the hardness that makes a portion is below the 250Hv, when the threading path of threaded portion is M12 when following, the hardness that makes a portion is to be significant below the 200Hv.
Then, the threading path of manufacturing double thread portion and 10 mean roughness (seat portion surface roughness) on seat portion surface carry out the sample of the spark plug of various changes, carrying out various kinds originally being installed to the testing stand of the aluminum of simulated engine head on the basis of various changes to concluding torque.And, when sample is heated to 150 ℃, be continuously applied by air under the pressure status of 1.5MPa, determining from the per 1 minute air leakage rate between sample and the testing stand to be that 2ml/ divides and concludes torque (minimum is concluded torque) when above according to each sample.In addition, we can say that minimum is concluded the little sample of torque, the sufficient air-tightness of easy more realization is favourable aspect air-tightness promptly.Fig. 6 is expression seat portion's surface roughness and the minimum chart of the relation of torque of concluding.And in Fig. 6, threading path is that the result of the test of the sample of M14 is drawn with dark circles, and threading path is that the result of the test of the sample of M12 is drawn with the black triangle, and threading path is that the result of the test of the sample of M10 is drawn with black diamonds.And the hardness of the seat portion of each sample is 150Hv, and the hardness at the position that contacts with seat portion in the testing stand is 100Hv.
As shown in Figure 6, be sample below the 12.5 μ m for seat portion surface roughness as can be known, it is small constant value that minimum is concluded torque, the minimum that seat portion surface roughness surpasses the sample of 12.5 μ m is concluded torque and is increased.That is, can know clearly that seat portion surface roughness surpasses in the sample of 12.5 μ m, is difficult to make a portion and head closely to contact, promptly be difficult to guarantee the sealing between a portion and head.Therefore, we can say that from realizing the angle of good air-tightness, making portion's surface roughness is to be significant below the 12.5 μ m.
(the 2nd execution mode)
, be that the center describes with difference especially in the time of with reference to accompanying drawing then with the 1st execution mode for the 2nd execution mode.
Spark plug 1A in this 2nd execution mode compares with above-mentioned the 1st execution mode, as shown in Figure 7, it is characterized in that, the seat portion 47 of main body covered accessory 3 is provided with coating 51A outwardly.The softening point of coating 51A is more than 200 ℃, and is formed by the little material of the hardness of the above-mentioned head 42 of hardness ratio (for example fluororesin etc.).Particularly, the Vickers hardness of the hardness of above-mentioned coating 51A is below the 100Hv.
And as shown in Figure 8, the thickness T H of above-mentioned coating 51A is the enough big accessory that 5 μ m are above, 300 μ m are following.And 10 mean roughness on the surface at the position that contacts with above-mentioned head 42 among the coating 51A are below the 12.5 μ m.
And, in the 2nd execution mode, compare the hardness difference of seat portion 47 with above-mentioned the 1st execution mode.That is, the Vickers hardness of the hardness of seat portion 47 surpasses for example 220Hv of 200Hv().
Above according to the 2nd execution mode, therefore the hardness of coating 51A can make coating 51A closely touch head 42 conscientiously, and can suppress the damage of head 42 conscientiously less than the hardness of head 42.And the softening point that forms the material of coating 51A is more than 200 ℃, therefore under the hot environment when using spark plug, can suppress the thermal deformation of coating 51A.That is,, can fully guarantee air-tightness in the combustion chamber by these action effects according to the 2nd execution mode.
Further, form the fluororesin elastically deformable of coating 51A, therefore repeatedly with spark plug to head 42 install/when taking off, also can prevent the distortion of coating 51A conscientiously.
And, because of the thickness setting of coating 51A is more than the 5 μ m, below the 300 μ m, therefore can make spark plug (coating 51A) closely be contacted with head 42 more effectively, realize bubble-tight further raising.
And, the Vickers hardness of the hardness of coating 51A is below the 100Hv, and 10 mean roughness on the surface, position that contacts with head among the above-mentioned coating 51A are below the 12.5 μ m, therefore can make spark plug (coating 51A) closely touch head more effectively.
Follow action effect in order to confirm that above-mentioned the 2nd execution mode plays, produce the sample that is provided with by the coating that fluororesin forms, the surface roughness difference is different, and coating is not set, to the sample that the surface roughness of seat portion is carried out various changes, each sample is measured above-mentioned minimum concludes torque.Fig. 9 is the surface roughness and the minimum chart of the relation of torque of concluding of expression coating (seat portion).And in Fig. 9, the result of the test of the sample that is provided with coating is drawn with dark circles, to the result of the test of sample that coating is not set with four jiaos of drawing of black.And making the hardness of the seat portion of each sample is 150Hv, and the hardness at the position that contacts with seat portion in the testing stand is 100Hv.And for the sample that is provided with coating, the thickness that makes coating is 50 μ m.
As shown in Figure 9, the sample that is provided with coating is compared with the sample that coating is not set, and regardless of the size of surface roughness, minimum is concluded torque and all diminished as can be known.Therefore, from being easy to realize the angle of good air-tightness, it is significant coating being set with covering seat portion.
Find that in addition when the surface roughness of coating surpassed 12.5 μ m, minimum was concluded torque and slightly increased.Therefore, in order to realize more good air-tightness more effectively, 10 mean roughness that preferably make above-mentioned coating surface are below the 12.5 μ m.
Then the threading path in the threaded portion is on the basis of M10 or M12, produces to have to cover seat portion surface and by the sample of the spark plug of fluororesin or zinc-plated that form, coating that thickness has carried out various changes, each sample is measured above-mentioned minimum conclude torque.Figure 10 is the thickness and the minimum chart of the relation of torque of concluding of expression coating.
In addition, when forming coating by fluororesin, the Vickers hardness of the hardness of this coating is 60Hv, and during by zinc-plated formation coating, the Vickers hardness of the hardness of this coating is 120Hv.And, in Figure 10, will be that the result of the test of the sample of M12 is drawn with dark circles by zinc-plated formation coating, threading path, will be that the result of the test of the sample of M10 is drawn with black triangle by zinc-plated formation coating, threading path.And, will by fluororesin form coating, threading path be the result of the test of sample of M12 with black four jiaos of drawing, will form coating, threading path by fluororesin is that the result of the test of sample of M10 is with the drawing of fork mark.
As shown in figure 10, as can be known the thickness of coating be the minimum of the above sample of 5 μ m to conclude torque be small constant value, the thickness of coating is concluded torque less than the minimum of the sample of 5 μ m and is increased.This be because, be enough big size more than the 5 μ m by the thickness that makes coating, can improve the tight contact of sample with respect to testing stand.
And as can be known, and compare by the sample of zinc-plated formation coating, the sample that forms coating by fluororesin can be realized more good air-tightness.This be because, the coating that forms by fluororesin has lower hardness, sample can closely be contacted with testing stand.
Therefore, from the bubble-tight angle of further raising, preferably present portion surface is provided with coating, and to make the thickness of this coating be more than the 5 μ m, further preferably makes the hardness of coating lower (100Hv is following).But when coating is blocked up, improves this action effect of air-tightness and possibly can't give full play to.Therefore, thickness that we can say coating is preferably below the 300 μ m.
(the 3rd execution mode)
, be that the center describes then with difference with the 1st execution mode for the 3rd execution mode.
Spark plug 1B in this 3rd execution mode as shown in figure 11, the formation difference of the 17A of seat portion especially.That is, in above-mentioned the 1st execution mode, the front end of above-mentioned seat portion 17 constitutes with the rear end of above-mentioned screw neck 16 with being connected, but in this 3rd execution mode, forms connecting portion 17B between the front end of the present 17A of portion and the rear end of screw neck 16.
And the threading path path of above-mentioned threaded portion 15 turns to below the M12, and above-mentioned wide diameter portion 18, instrument buckling parts 19 and be same size before substantially.Therefore as shown in figure 12, if the external diameter of the front end of above-mentioned wide diameter portion 18 is A(mm), the external diameter of external diameter becomes minimum in the above-mentioned screw neck 16 part is B(mm) time, (A-B)/2 be more than the 0.8mm, promptly A-B is the bigger value of 1.6mm above (for example more than the 2.0mm).In addition, when making the extreme big footpathization of wide diameter portion 18,, can damage the degree of freedom of layout for the engine of having assembled spark plug 1B.Therefore, the external diameter of the front end of above-mentioned wide diameter portion 18 is below the 19.0mm.
Further, in the 3rd execution mode, the following setting of boundary position of above-mentioned seat 17A of portion and connecting portion 17B.That is, the external diameter of the boundary member of choose a place to give a banquet 17A of portion and connecting portion 17B is C(mm) time, (C-B)/2 be more than the 0.3mm, and (A-C)/2 determine the boundary position of a 17A of portion and connecting portion 17B abovely for 0.7mm.
And, 17A of seat portion and connecting portion 17B all are the tapers that attenuate towards axis CL1 direction front, but in the cross section that comprises axis CL1, compare with axis CL1 angulation α 1 with the object line of the 17A of seat portion (extended line), the object line of connecting portion 17B (extended line) and axis CL1 angulation α 2 are bigger.Therefore as shown in figure 13, when the installing hole 43 of the head 42 that spark plug 1B is installed to internal combustion engine 41, connecting portion 17B does not contact with head 42, and only bottom 17A closely is contacted with head 42.
And in the 3rd execution mode, the object line of the above-mentioned seat 17A of portion and axis CL1 angulation α 1 are more than 60 degree, below 70 degree.
According to the 3rd execution mode, in the cross section that comprises axis CL1, compare with the 17A of seat portion angulation α 1 with axis CL1, axis CL1 and connecting portion 17B angulation α 2 are bigger.That is, when spark plug 1B was installed to internal combustion engine 41, only the 17A of seat portion closely was contacted with head 42 ground formation.So, compare when closely being contacted with head 42, can reduce the area at the position that closely is contacted with head 42, do not increase and conclude power and can make spark plug 1B closely be contacted with head 42 more effectively with 17A of seat portion and whole of connecting portion 17B.The result can fully guarantee the air-tightness in the combustion chamber.
And,, can prevent that the area of the 17A of portion from excessively increasing, and, can fully keep the area of the 17A of portion by making (A-C)/2＜0.7mm by making (C-B)/2＜0.3mm.Therefore, can prevent conscientiously further that air-tightness from reducing.
Further, axis CL1 and the 17A of seat portion angulation α 1 are more than 60 degree, so can prevent that a 17A of portion is trapped in the head 42, even in the installation of repeatedly carrying out spark plug 1B/when taking off, also can guarantee good air-tightness.On the other hand, above-mentioned angle [alpha] 1 is below 70 degree, therefore can fully improve the tight contact of a 17A of portion to head 42, realizes good air-tightness.
(the 4th execution mode)
Then for the 4th execution mode, be that the center describes with difference in the time of with reference to accompanying drawing with the 3rd execution mode.
Spark plug 1C in the 4th execution mode compares with above-mentioned the 3rd execution mode, shown in Figure 14,15, it is characterized in that, the bottom 47A of main body covered accessory 3 is provided with the position that has added diffusing some decorative pattern among coating 51B(Figure 14 outwardly).
In addition, coating 51B is the same with coating 51A in above-mentioned the 2nd execution mode, is more than 200 ℃ and Vickers hardness is that the hardness materials with smaller (for example fluororesin etc.) of (for example 60Hv is following) below the 100Hv forms by softening point.Therefore, the hardness of above-mentioned coating 51B is less than the hardness of above-mentioned head 42.And the surface roughness of coating 51B is below the 12.5 μ m, and its thickness T H is more than the 5 μ m, below the 300 μ m.
Follow action effect in order to confirm that above-mentioned the 3rd execution mode plays, the threading path that makes the threaded portion is M12 or M10, and the instrument buckling parts of making is HEX16 or HEX14, on this basis the value of (C-B)/2 and value (A-C)/2 are carried out various changes, thereby the sample of the spark plug of various changes has been carried out in the position of making a plurality of boundary members to seat portion and connecting portion, and each sample is carried out above-mentioned air-tightness evaluation test.And in this test, when the leakage of air amount is the 0.1(ml/ branch) when following, can realize utmost point good air-tightness, make the evaluation of " ◎ ", when the leakage of air amount is the 0.1(ml/ branch) more than, less than the 0.2(ml/ branch) time, can realize good air-tightness, make the evaluation of " zero ".On the other hand, when the leakage of air amount is the 0.2(ml/ branch) when above, air-tightness is slightly not good, makes the evaluation of " △ ".In addition, be the sample of M12 for threading path, A-B is 3.6mm, is the sample of M10 for threading path, A-B is 3.5mm.And for the object line and the axis angulation (seat portion angle) of seat portion, each sample is 63 degree.Further, each sample carries out with the torque of concluding of regulation to the installation of testing stand.The result of table 1 and table 2 expression evaluation test.In addition, the result of the sample of table 1 expression threading path M12, HEX16, the result of the sample of table 2 expression threading path M10, HEX14.And the area of having represented seat portion in each table in the lump.
(table 1)
(table 2)
Shown in table 1 and table 2, (C-B)/2 are for realizing good air-tightness for the above sample of 0.7mm more than the 0.3mm and (A-C)/2 as can be known.This be because, by making (C-B)/2 〉=0.3mm, can reduce the area of the seat portion that closely is contacted with head, concluding torque when spark plug is installed by afore mentioned rules, also can make a portion closely be contacted with testing stand, and by making (A-C)/2 〉=0.7mm, can fully guarantee the area of a portion, fully guarantee the sealing between a portion and the head.
Then, the threading path of making the threaded portion of sening as an envoy to is M12 or M10, and the instrument buckling parts of making is HEX16 or HEX14, on this basis above-mentioned seat portion angle is carried out the sample of the spark plug of various changes, and each sample is carried out above-mentioned air-tightness evaluation test.In addition, estimate substantially the evaluation of making " ◎ " when following etc. with said method (the leakage of air amount is the 0.1(ml/ branch)) identical method carries out, though can realize good air-tightness but finding after taking off sample that testing stand has under the situation of depression equivalent damage, when the installation of carrying out spark plug repeatedly/when taking off, air-tightness may reduce, and makes the evaluation of " ※ ".Table 3 and table 4 expression result of the test.In addition, threading path is in the sample of M12, (C-B)/2 is that 0.75mm, (A-C)/2 are 1.05mm, and threading path is in the sample of M10, (C-B)/2 is that 0.75mm, (A-C)/2 are 1.00mm.The result of the sample of table 3 expression threading path M12, HEX16, the result of the sample of table 4 expression threading path M10, HEX14.
(table 3)
| Seat portion angle (°) | Area (the mm of seat portion 2) | Estimate |
| 35 | 159.6 | ※ |
| 40 | 140.3 | ※ |
| 45 | 125.4 | ※ |
| 50 | 113.6 | ※ |
| 55 | 103.9 | ※ |
| 60 | 96.0 | ◎ |
| 65 | 89.3 | ◎ |
| 70 | 83.7 | ◎ |
| 75 | 78.8 | ○ |
| 80 | 74.7 | ○ |
| 85 | 71.0 | ○ |
(table 4)
Shown in table 3,4, each sample standard deviation can be realized good air-tightness, and particularly seat portion angle is that testing stand does not produce damage, can realize utmost point good air-tightness in the sample that 60 degree are above, 70 degree are following.
By above result of the test as can be known, from the combustion chamber, guaranteeing the more angle of good air-tightness, make (C-B)/2 above and make (A-C)/2 for being significant more than the 0.7mm for 0.3mm.And from realizing the more angle of good air-tightness, seat portion angle is that 60 degree are above, especially meaningful below 70 degree.
And, be not limited to the record content of above-mentioned execution mode, for example also can followingly implement.Certainly, other application examples of example, modification are not possible yet below.
(a) in above-mentioned the 1st execution mode, only use cut to make main body accessory intermediate, thereby the hardness that makes above-mentioned seat portion 17 is 250Hv following (200Hv is following), is that the method for 250Hv following (200Hv is following) is not limited thereto but make the hardness of a portion 17.For example except cut, also can and use and forge processing, to main body accessory 3(seat portion 17) implement heat treated, be (200Hv is following) below the 250Hv thereby also can use the hardness of a portion 17.And, also can be by the metal material (when for example using carbon steel to form main body accessory 3) of change formation main body accessory 3 by reducing the carbon element amount, the hardness that makes a portion 17 is 250Hv following (200Hv is following).But when change constitutes the metal material of main body accessory 3, should be noted that the intensity of fully guaranteeing threaded portion 15, caulking part 20 etc.
(b) in above-mentioned the 1st execution mode, the hardness of seat portion 17 integral body is 250Hv following (200Hv is following), but also can be that the hardness at the position that contact with head 42 at least in the portion 17 is (below the 200Hv) below the 250Hv.
(c) in above-mentioned the 1st, the 2nd execution mode, the 17(47 of seat portion) form taper, but the 17(47 of seat portion) shape be not limited thereto.Therefore, for example also can make a 17(47 of portion) screw neck 16, wide diameter portion 18 form orthogonally relatively.
(d) in above-mentioned the 3rd, the 4th execution mode, connecting portion 17B forms the taper that attenuates to axis CL1 direction front end one side, but the shape of connecting portion 17B is not limited thereto.For example also can be, to form connecting portion 17B along extending to axis CL1 one side with the direction of axis CL1 quadrature.
(e) in above-mentioned the 3rd execution mode, A-B is below the 1.6mm, but the value of A-B is not limited thereto.
(f) in above-mentioned the 3rd execution mode, the threading path of threaded portion 15 is below the M12, and A-B is more than the 1.6mm, but under, the situation such as A-B is bigger littler at the threading path of threaded portion 15, the present invention that connecting portion 17B is set is significant.Therefore, especially, by the threading path that technological thought of the present invention is applicable to threaded portion 15 be below the M10, A-B is the spark plug more than the 2.0mm, can effectively prevent bubble-tight reduction.
(g) in above-mentioned the 2nd, the 4th execution mode, the Vickers hardness of the hardness of coating 51A, 51B is below the 100Hv, but the hardness of coating 51A, 51B is not particularly limited to this, and the hardness of coating 51A, 51B also can surpass 100Hv.In addition, the hardness of coating 51A, 51B is crossed when hanging down, and it is not enough that the intensity of coating 51A, 51B may become, so the hardness of coating 51A, 51B is preferably more than the 35Hv.
(h) in above-mentioned the 2nd, the 4th execution mode, as the material that forms coating 51A, 51B, example fluororesin, but the material that forms coating 51A, 51B is not limited thereto, so long as softening point more than 200 ℃ and hardness get final product less than the material of the hardness of head 42.For example also can use thermal endurance rubber (for example fluorubber), other heat-resistant resins (for example polyimides is resin, polyamide-based resin etc.) to form coating 51A, 51B.And, also can form coating with the little metal material of the hardness of the above-mentioned head 42 of hardness ratio (for example zinc etc.).But when forming coating by zinc etc., zinc-plated, the nickel plating that preferably obtains than the roughly whole surf zone that is formed at main body accessory 3 more heavy back forms coating (for example more than the 10 μ m).
(i) though do not mention in the above-described embodiment, also can noble metal chip be set any one or both sides of central electrode 5 and grounding electrode 27.In this case, spark-discharge gap 33 is formed on an electrode 5(27) and another electrode 27(5) between the noble metal chip that go up to be provided with or between two noble metal chips that are provided with on two electrodes 5,27.
(j) in the above-described embodiment, the situation that grounding electrode 27 is attached to the leading section 26 of main body accessory 3 is specialized, but also goes for following situation: cut out the main body accessory the part part of the front end accessory of main body accessory (or be welded in advance) form grounding electrode (for example the spy opens 2006-236906 communique etc.).
(k) in the above-described embodiment, instrument buckling parts 19 is cross section hexagonal configurations, but the shape of instrument buckling parts 19 is not limited thereto.For example also Bi-HEX(be out of shape 12 jiaos) shape (ISO22977:2005(E)) etc.
Claims (3)
1. ignition plug for I. C. engine has:
The bar-shaped central electrode that on axis direction, extends;
Be arranged on the insulator roughly cylindraceous of the periphery of above-mentioned central electrode;
Be arranged on the roughly cylindrical main body accessory of above-mentioned insulator periphery; And
Grounding electrode from the leading section extension of aforementioned body accessory, and forms the gap between the leading section of leading section of self and above-mentioned central electrode,
Outer peripheral face at the aforementioned body accessory is formed with:
The threaded portion that screws togather with the installing hole of the head of internal combustion engine;
Be formed on the screw neck of the rear end side of above-mentioned threaded portion;
Be formed on the rear end side of above-mentioned screw neck, the wide diameter portion that diameter is bigger than above-mentioned screw neck; And
Seat portion between above-mentioned screw neck and above-mentioned wide diameter portion,
Above-mentioned ignition plug for I. C. engine is characterised in that,
The surface of above-mentioned seat portion is provided with coating, and this coating covers this surface, and when the installing hole of the head of above-mentioned threaded portion and above-mentioned internal combustion engine screws togather, closely contacts with above-mentioned head,
Above-mentioned coating forms by following material: its softening point is more than 200 ℃, and the hardness of the part that contacts with above-mentioned coating in the above-mentioned head of hardness ratio is little.
2. ignition plug for I. C. engine according to claim 1 is characterized in that,
The Vickers hardness of the hardness of above-mentioned coating is below the 100Hv,
And 10 mean roughness on the surface, position that contacts with above-mentioned head in the above-mentioned coating are below the 12.5 μ m.
3. ignition plug for I. C. engine according to claim 1 and 2 is characterized in that,
Above-mentioned coating has the thickness that 5 μ m are above, 300 μ m are following.
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| JP2009-012898 | 2009-01-23 | ||
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| CN201080003648.4A Division CN102257687B (en) | 2009-01-23 | 2010-01-21 | Spark plug for internal combustion engine |
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| CN201080003648.4A Active CN102257687B (en) | 2009-01-23 | 2010-01-21 | Spark plug for internal combustion engine |
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| US (1) | US8970097B2 (en) |
| EP (1) | EP2390973B1 (en) |
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| CN111799658A (en) * | 2019-04-01 | 2020-10-20 | 日本特殊陶业株式会社 | Spark plug |
| CN111799657A (en) * | 2019-04-01 | 2020-10-20 | 日本特殊陶业株式会社 | Spark plug |
| CN111834918A (en) * | 2019-04-16 | 2020-10-27 | 日本特殊陶业株式会社 | Spark plug |
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| JP5526161B2 (en) * | 2012-01-12 | 2014-06-18 | 日本特殊陶業株式会社 | Spark plug manufacturing method and metal shell manufacturing method |
| JP5572181B2 (en) * | 2012-06-12 | 2014-08-13 | 日本特殊陶業株式会社 | Spark plug and manufacturing method thereof |
| JP5903005B2 (en) * | 2012-07-05 | 2016-04-13 | 日本特殊陶業株式会社 | Glow plug |
| JP5369227B1 (en) | 2012-07-30 | 2013-12-18 | 日本特殊陶業株式会社 | Spark plug |
| EP3148019A4 (en) * | 2014-05-19 | 2018-01-24 | NGK Spark Plug Co., Ltd. | Plug connector, rubber member, and ring member |
| GB2545656A (en) * | 2015-12-18 | 2017-06-28 | Caterpillar Energy Solutions Gmbh | Spark plug |
| JP6373447B2 (en) * | 2016-11-29 | 2018-08-15 | 日本特殊陶業株式会社 | Spark plug |
| CN108123367A (en) * | 2016-11-29 | 2018-06-05 | 日本特殊陶业株式会社 | Spark plug |
| JP6812329B2 (en) * | 2017-11-27 | 2021-01-13 | 日本特殊陶業株式会社 | How to make a spark plug |
| JP6817252B2 (en) * | 2018-06-22 | 2021-01-20 | 日本特殊陶業株式会社 | Spark plug |
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2010
- 2010-01-21 EP EP10733511.9A patent/EP2390973B1/en active Active
- 2010-01-21 US US13/138,198 patent/US8970097B2/en active Active
- 2010-01-21 CN CN2013100491225A patent/CN103227420A/en active Pending
- 2010-01-21 WO PCT/JP2010/050683 patent/WO2010084904A1/en active Application Filing
- 2010-01-21 JP JP2010519039A patent/JP5331114B2/en active Active
- 2010-01-21 CN CN201080003648.4A patent/CN102257687B/en active Active
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2012
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| US6548945B1 (en) * | 1999-10-21 | 2003-04-15 | Denso Corporation | Spark plug and method of manufacturing the same |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111799658A (en) * | 2019-04-01 | 2020-10-20 | 日本特殊陶业株式会社 | Spark plug |
| CN111799657A (en) * | 2019-04-01 | 2020-10-20 | 日本特殊陶业株式会社 | Spark plug |
| CN111799657B (en) * | 2019-04-01 | 2022-02-22 | 日本特殊陶业株式会社 | Spark plug |
| CN111834918A (en) * | 2019-04-16 | 2020-10-27 | 日本特殊陶业株式会社 | Spark plug |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102257687A (en) | 2011-11-23 |
| JP2013033755A (en) | 2013-02-14 |
| JP5514280B2 (en) | 2014-06-04 |
| EP2390973A4 (en) | 2014-09-10 |
| CN102257687B (en) | 2014-01-29 |
| EP2390973A1 (en) | 2011-11-30 |
| US20110273074A1 (en) | 2011-11-10 |
| JP5331114B2 (en) | 2013-10-30 |
| EP2390973B1 (en) | 2016-10-26 |
| WO2010084904A1 (en) | 2010-07-29 |
| US8970097B2 (en) | 2015-03-03 |
| JPWO2010084904A1 (en) | 2012-07-19 |
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